What going on here

[Cryptocaryon]

Mounds forming in my favia with two antennae poking out. Anyone know about this?

 

[Crabs McJones]

Encrusting over vermedit snail tubes possibly?

 

[KJ]

Polychaete Chaetopterid. (Tube Worm)

 

[MnFish1]

Mounds forming in my favia with two antennae poking out. Anyone know about this?

I had something like this on a couple goniopora that I bought - occasionally there would be 'bubbles' - underneath the coral when it was stressed - like the coral was coming away from the skeleton in those places. Curious - is this a relatively new coral for your tank? there are some areas that look like tube worms - but its unclear since there is only one picture. I will say that its not a 'good sign' but rather at best a sign of stress - at worse - something else.